The first night of Rock the Bells at Randall's Island, set for Saturday, July 28th, sold out in 20 minutes. Seemed good enough reason for Guerilla Union (helped out by, erm, Live Nation) to add a second date on that Sunday, July 29th. Guerilla Union has so far confirmed that Saturday's headliners, Rage Against the Machine and Wu Tang Clan, along with Cypress Hill, will play both dates.
Unclear if Guerilla Union plans to set up a whole separate lineup (seeing as there are more than twenty other acts lined up for Saturdya's performance) for Sunday. Tickets go on sale May 4.